More Watts vs More Speakers

[dnarock]

+1 speakers

 

[Mike151]

I run 750w into 1-15 and a 2-10. This is pleanty of volume for my situation however if I wanted more volume, I would go with more speakers. The more surface area pushing air, the more volume IMO.

 

[Metal Matt]

That would put twice as much power in the 2x10 as the 4x10.

I guess I'm probably thinking of this in way too simple terms. That with two cabs of the same impedance, the one with less speaker area would be quieter because it's not pushing as much air, so to correct for it you'd want the cab that's moving less air, to have more power going to it.

But then again, I don't know a whole lot about the technical side of this stuff, aside from knowing the basic impedance info needed to not blow up an amp.

 

[butchblack]

True, but 'that's the way we've always done it' is hardly a compelling reason to do so. The combination of a 2x10 and 4x10 is a good one, but only if the impedances are properly matched so that each ten receives the same power input.

How would you do that Bill? a 4Ω 410 and an 8Ω 210? which would be 3.something overall Ω's

 

[johnk_10]

you would need four 16 ohm speakers wired parallel in the 4x10 cab and two 16 ohm speakers wired in parallel in the 2x10 cab

 

[afroman]

definitely more cabs.
Altough running an 810 with 50 non-tube watts wouldn't sound very good. Clipping issues aside, more speakers is better IME.

 

[johnk_10]

after running two V4 4x12 cabs today with my V4B today, i can attest that having more speakers is definitely the best way to increase your amp's loudness. a V4 head is only 108 watts (but a healthy 108 watts). the V4B head running thru two cabs, sounded easily as loud as a 300 watt SVT running thru one of the 4x12 cabs.

 

[aborgman]

How would you do that Bill? a 4Ω 410 and an 8Ω 210? which would be 3.something overall Ω's

It would be an overall impedance of 2.67 ohms, and yes - with that arrangement each speaker would be receiving the equal power.

 

[billfitzmaurice]

How would you do that Bill? a 4Ω 410 and an 8Ω 210? which would be 3.something overall Ω's

That's why I mentioned the 16 ohm 2x10/8 ohm 4x10 option, for a total 5.3 ohm load that most amps would be comfortable with. 16 ohm 2x10s are rare, but it's just a 4 ohm 2x10 with the drivers wired series instead of parallel.

 

[dannster]

It would be an overall impedance of 2.67 ohms, and yes - with that arrangement each speaker would be receiving the equal power.

Now explain what happens when an amp that will only go down to 4ohms (as "most" do) is given a 2.67 ohm load.

This is where the uninformed get into trouble and was my original point about worrying about getting the exact amount of watts to each speaker without careful regard for what your amp can handle.

 

[aborgman]

Now explain what happens when an amp that will only go down to 4ohms (as "most" do) is given a 2.67 ohm load.

That depends on how much current you try to draw from it. Don't run it hard, and chances are it will handle it just fine. Run it hard and you'll exceed the current sinking/sourcing ability of the output device in the amp - then it'll either overheat, or worst case start letting out the magic smoke.

This is where the uninformed get into trouble and was my original point about worrying about getting the exact amount of watts to each speaker without careful regard for what your amp can handle.

I wouldn't advise people who don't have at least a basic understanding of Ohms law not be pairing up cabinets and hanging them off their amp without some advice from someone with that knowledge.

 

[insomniac2295]

so, why is using an 8 ohm 210 and an 8 ohm 410 together such a big deal? So what if the 210 gets more power. The 410 has twice the speaker surface area than the 210. Wouldn't that make them sound more even in terms of volume? And what about guitarist who use a 412+212 setup, or a 212 or 112 combo with a 412 extension cab?

 

[Mulebagger]

I've never had much luck pairing speakers unless they were the two of the same. These days I have a BagEnd 2x10 4 ohm for small to medium gigs and a Mesa 6x10 4 ohm for large and outdoor gigs. combining the two could work, but I would never need that much power... well not if I ever want to hear again.

Try to find a good single cab that works well for all or most of your gigging needs. Maybe an Aguilar 2x12 or a Bag End 2x10. If you need more juice than that, rent or borrow a bigger cab.

 

[aborgman]

so, why is using an 8 ohm 210 and an 8 ohm 410 together such a big deal?

It may or may not be depending on the cab in question.

Why it may be a big deal - the 2x10 is gettin gtwice the power per speaker of the 4x10, so your volume will be limited by the max power handling of the 2x10.

If your amp puts out 600W @ 4ohms (which is what the impedance seen by the amp would be) the 2x10 will get 300W, and the 4x10 will get 300W.

Lets say the 4x10 has a max input power of 300W. The 2x10 with the same speakers has a max input power of 150W. See the problem?

You can never get all the volume possible out of the 4x10 without ruining the 2x10.

So what if the 210 gets more power. The 410 has twice the speaker surface area than the 210.

Speaker area doesn't tell us much. What is of interest in the sensitivity of each cab. If the 410 is 3dB more sensitive than the 210, then it will take twice as much power fed to the 210 to make its volume equal to the 410.

Wouldn't that make them sound more even in terms of volume?

Maybe. Or maybe less even. It will all depend on cabinet sensitivity.

If the 4x10 is 100dB/W @ 1 M and the 2x10 is 97dB/W @ 1M - then the 2x10 with twice the power will be equal in volume.

If the 4x10 is 97dB/W @ 1 M and the 2x10 is 97dB/W @ 1M - then the 2x10 with twice the power will be 3dB louder than the 410.

If the 4x10 is 97dB/W @ 1 M and the 2x10 is 100dB/W @ 1M - then the 2x10 with twice the power will be 6dB louder than the 410.

...and yes, if you mix cabinets from different manufacturers or product lines you can find a 410 with a lower sensitivity than a 210, even given all the extra cone area on the 410.

And what about guitarist who use a 412+212 setup, or a 212 or 112 combo with a 412 extension cab?

They may have the same issue, and they may not. We're talking about paralleling two cabs off a single channel amp. A lot of guitar amps are dual channel. If the two different cabs are on two different channels, it becomes much less of an issue - at least if you have any way of controlling the volume balance between the two channels.

-

 

[billfitzmaurice]

The 410 has twice the speaker surface area than the 210. Wouldn't that make them sound more even in terms of volume? ?

No. The way to think of this is if all six drivers were in the same box, as a 6x10. For them all to have the same output they would have to be wired in exactly the same way as they would to arrive at the 2:1 impedance ratio of 2x10 to 4x10. You would not wire a 6x10 so that half the power was going to two of the drivers with the other half split amongst the remaining four.